1. Field of the Invention
The present invention relates to an air-cooling apparatus for a projection television and, more particularly, to an air-cooling apparatus for a projection television by which heat emitting elements disposed in an image projector of the projection television can be concentratedly air-cooled thereby preventing the heat emitting elements from being over-heated and which can simplify the internal structure of the projection television.
2. Description of the Related Art
Generally, a projection television is an appliance for projecting an image onto a transmission screen. Such a projection television uses cathode ray tubes or a liquid crystal panel.
FIG. 1 shows a schematic sectional view of a projection television using the liquid crystal panel. A body 10 of the projection television consists of a front casing 11, a rear casing 12 and a base 13 which form an external appearance of the projection television. A beam transmission screen 20 is installed in the front casing 11. Installed within the body 10 are an image projector 30 and a reflection mirror 40 for reflecting a beam from the image projector 30 to the screen 20.
FIG. 2 schematically shows a beam path of the image projector 30. The image projector 30 is provided at one side thereof with a beam source 31. A lens 32 for focusing a beam radiated from the beam source 31 is installed at the front of the image projector 30. At one side of the lens 32, there are provided three dichroic mirrors 33 which are inclined and only reflect predetermined colors (red, green, and blue) for obtaining a desired color.
In order to form an image having a length and a breadth in the ratio of 16:9, a liquid crystal panel 34 having a plurality of liquid crystal elements (not shown) therein and a projection lens 35 are disposed at one side of the dichroic mirrors 33. Projection lens 35 radiates a beam, which corresponds to an image formed from the liquid crystal panel 34, toward the reflection mirror 40. Reflection mirror 40 reflects the beam radiated from the projection lens 35 toward the screen 20. In order to form a beam path from the projection lens 35 to the screen 20, the reflection mirror 40 has a predetermined inclined angle and is fixedly installed within the rear casing 12.
In addition, a blowing fan 36 is disposed adjacent to the image projector 30 so as to attempt to dissipate the heat which is generated when the image projector 30 operates and thereby cool the image projector 30.
In the projection television having the above construction, the beam corresponding to the image formed from the liquid crystal panel 34 is radiated through the projection lens 35, and the radiated beam is reflected to a rear side of the screen 20 by the reflection mirror 40, thereby projecting an image onto the screen 20.
At the same time, the blowing fan 36 is driven so that the heat emitting elements, such as the beam source 31, the dichroic mirrors 33, the liquid crystal panel 34 and the projection lens 35, are air-cooled.
However, the conventional projection television having the blowing fan 36 for air-cooling the image projector has a problem. That is, since the blowing fan 36 is simply provided adjacent to the image projector 30, air blown by blowing fan 36 goes past by beam source 31, dichroic mirrors 33, the liquid crystal panel 34 and the projection lens 35, so that the heat emitting elements are not sufficiently air-cooled. Accordingly, the heat emitting elements of the image projector are subjected to an over-heat condition.
In addition, a separated duct is required to be installed in the casing for guiding air blown by the blowing fan, so that not only is the space for installing the duct required, but also the internal structure of the projection television is complicated.